P2730

Press Ctrl Solenoid E Ctrl Circ High

Indicator

The PCM has detected an abnormality in a particular electronic pressure control solenoid or solenoid circuit. The computer controlled automatic transmission uses varying degrees of hydraulic pressure to provide shift actuation and torque converter lockup. Pressure is regulated using one or more electronic pressure control solenoids which are controlled by the PCM.

Code Set Parameters

Although code setting parameters vary greatly from one manufacturer (and model) to another, virtually every application utilizes calculations based upon throttle position, engine load, engine speed, and vehicle speed to determine the desired degree of pump pressure required for efficient operation. If the desired amount of fluid pressure fails to coincide with the actual amount detected, a code will be stored and a malfunction indicator lamp may be illuminated. Some applications require multiple failure cycles in order for a service engine soon lamp to be illuminated.

Symptoms

These may vary from no detectable symptoms at all to disabled shifting function and a failure of the torque converter clutch to engage/disengage. This code may also be accompanied by the PCM placing the transmission in "limp-in" mode. Other symptoms may include harsh shifting, transmission slippage, transmission overheating, decreased fuel efficiency, a stored code, and possibly an illuminated malfunction indicator lamp. Other torque converter clutch, lock up, gear ratio, shift solenoid, or transmission slippage codes often accompany this code.

Common Misdiagnosis

Technicians report that electronic pressure control solenoid and wiring malfunctions are often overlooked and high pressure pumps are frequently replaced in error.

Diagnosis

A scanner (or code reader) and a digital volt/ohmmeter will be required to successfully diagnose this code.
Virtually every vehicle (with an automatic transmission) produced since the mid-eighties is equipped with some type of computer controlled automatic transmission system

The PCM calculates input data and regulates transmission fluid pressure via a specially designed pressure control solenoid.
The automatic transmission uses a high pressure pump (driven by the engine via the torque converter) to circulate fluid through the transmission hydraulic circuits in the transmission housing and valve body

If transmission pressure is insufficient to actuate gear changes, this type of code may be present

Insufficient fluid pressure is most often caused by a low or dirty (contaminated) transmission fluid condition

Begin any transmission diagnosis with an inspection of the transmission fluid dipstick (if equipped)

At any rate, make sure that the fluid level is within manufacturer's specified recommendations and that the fluid is in good condition

Fluid that smells burned or abnormal in any way should be considered inadequate

Burned fluid is a certain indication that the transmission has been operated during a low fluid level condition and may have suffered catastrophic internal mechanical failure

If the fluid smells or appears burned, remove the transmission pan and check for the presence of clutch material and other debris

If such contaminants are found in the transmission pan, a total rebuild, fluid flush and replacement, and a new torque converter will be required before the transmission will function properly.
If no debris is found in the transmission pan, visually inspect all internal wiring and connectors

Look for shorted or burned wiring and replace circuitry and connectors as required

Most applications will require replacement of the full internal transmission harness if discrepancies are noted

If the system wiring, connectors, and components appear to be in normal working order, connect the scanner to the diagnostic connector and record all stored trouble codes and freeze frame data

This information can be extremely helpful in diagnosing intermittent conditions that may have contributed to this code being stored

After the codes are cleared, operate the vehicle to see if the code returns

If the code fails to immediately return, you may have an intermittent condition

Intermittent conditions can prove to be quite a challenge to diagnose and in extreme cases may have to be allowed to worsen before a correct diagnosis can be made

If the transmission fluid appears to be in decent shape, but the fluid level is low, add enough fluid to locate a leak and repair it

Fill the transmission with fluid, allow the vehicle to reach normal operating temperature, and test drive it to see if the transmission operates normally and to determine whether the code will return

If the transmission functions normally and the code doesn't return, then it was likely caused by transmission slippage due to a low fluid level/pressure condition.
If the code returns and the transmission slips or suffers from delayed engagement, check pump pressure using a manual pressure gauge

Obtain a hydraulic pressure diagram pertaining to the vehicle in question and thread the end of the gauge into the appropriate opening on the transmission housing to record pump pressure

Compare your findings with manufacturer's specifications and make repairs accordingly

If the code immediately returns, and the transmission seems to operate normally, check for reference voltage and ground signals at the electronic pressure control solenoid in question

If either the reference voltage or ground circuits are open, use the digital volt/ohmmeter to check for continuity (disconnect all related control modules from the circuit before checking circuit resistance or controller damage may occur) and resistance in all circuits

Repair or replace system circuits/connectors as required and retest the system to ensure that repairs were successful.
Using the manufacturer's wiring diagram for the electronic pressure control solenoid, test all related circuits and the solenoid itself for resistance and continuity and compare your findings with manufacturer's specifications

Repair or replace system circuitry, connectors, and/or components that fail to coincide with manufacturer's specs

Always retest the system to ensure a successful repair.
If all system circuits are intact connect the scanner to the diagnostic connector and attempt to manually activate the electronic pressure control solenoid

If the control solenoid functions properly and all circuits coincide with manufacturer's specifications, suspect a defective high pressure pump, torque converter, or PCM

Remember that PCM failure is rare and replacement will require reprogramming

If the electronic pressure control solenoid fails to activate manually, replace the solenoid and retest the transmission control system.